Dynamic protection against failure of a head-end node of one or more TE-LSPs

Abstract

A technique dynamically protects against failure of a head-end node of one or more primary Traffic Engineering Label Switched Paths (TE-LSPs) in a computer network. According to the novel technique, a neighboring upstream node (“protecting node”) of the head-end node learns of the primary TE-LSPs (and their respective state control blocks) extending from the head-end node to one or more address prefixes. The protecting node establishes a repair TE-LSP for each of the primary TE-LSPs to a corresponding downstream neighboring node of the head-end node (a “next-next-hop”). In response to detecting a failure of the head-end node, the protecting node locally reroutes traffic destined for the address prefixes to an appropriate repair TE-LSP. Due to the failure of the head-end node, the protecting node then refreshes the states of the primary TE-LSPs using replicated state control blocks accordingly, until the repair TE-LSPs are no longer needed.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to computer networks and more particularly to protection against failure of a head-end node of one or more Traffic Engineering Label Switched Paths (TE-LSPs) in a computer network. [0003] 2. Background Information [0004] A computer network is a geographically distributed collection of nodes interconnected by communication links and segments for transporting data between end nodes, such as personal computers and workstations. Many types of networks are available, with the types ranging from local area networks (LANs) to wide area networks (WANs). LANs typically connect the nodes over dedicated private communications links located in the same general physical location, such as a building or campus. WANs, on the other hand, typically connect geographically dispersed nodes over long-distance communications links, such as common carrier telephone lines, optical lightpaths, synchronous optica...

AI Technical Summary

Benefits of technology

[0025] Advantageously, the novel technique dynamically protects against failure of a head-end node of one or more primary TE-LSPs in a computer network. By establishing repair TE-LSPs around the head-end node, the novel technique allows a protecting node to quickly reroute traffic onto the repair TE-LSPs to the primary TE-LSPs in the event of head-end node failure. In particular, the use of repair TE-L...

Problems solved by technology

Since management of interconnected computer networks can prove burdensome, smaller groups of computer networks may be maintained as routing domains or autonomous systems.

In certain network configurations (e.g., with a large number of PE routers), however, this results in a large number of TE-LSPs throughout the network.

Occasionally, a network element (e.g., a node or li...

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